Documents in the NTIS Technical Reports collection are the results of federally funded research. They are directly submitted to or collected by NTIS from Federal agencies for permanent accessibility to industry, academia and the public.  Before purchasing from NTIS, you may want to check for free access from (1) the issuing organization's website; (2) the U.S. Government Printing Office's Federal Digital System website http://www.gpo.gov/fdsys; (3) the federal government Internet portal USA.gov; or (4) a web search conducted using a commercial search engine such as http://www.google.com.
Accession Number N20130010988
Title Application of Out-of-Plane Warping to Control Rotor Blade Twist.
Publication Date Jan 2012
Media Count 5p
Personal Author O. Bauchau S. Kottapalli S. Ozbay Y. Mehrotra Y. VanWeddingen
Abstract The goal of this ongoing study is to develop and demonstrate the feasibility of a blade actuation system to dynamically change the twist, and/or the camber, of an airfoil section and, consequently, alter the in-flight aerodynamic loading on the blade for efficient flight control. The required analytical and finite element tools are under development to enable an accurate and comprehensive aeroelastic assessment of the current Full-Blade Warping and 3D Warping Actuated Trailing Edge Flap concepts. The feasibility of the current concepts for swashplateless rotors and higher harmonic blade control is also being investigated. In particular, the aim is to complete the following objectives, some of which have been completed (as noted below) and others that are currently ongoing: (i) Develop a Vlasov finite element model and validate against the ABAQUS shell models (completed). (ii) Implement the 3D warping actuation concept within the comprehensive analysis code DYMORE. (iii) Perform preliminary aeroelastic simulations of blades using DYMORE with 3D warping actuation: (a) Investigate the blade behavior under 1 per/rev actuation. Determine whether sufficient twist can be generated and sustained to achieve primary blade control; (b) Investigate the behavior of a trailing edge flap configuration under higher harmonic excitations. Determine how much twist can be obtained at the harmonics 2-5 per/rev. (iv) Determine actuator specifications such as the power required, load and displacements, and identify the stress and strain distributions in the actuated blades. In general, the completion of Item (ii) above will give an additional research capability in rotorcraft dynamics analyses, i.e., the capability to calculate the rotor blade twist due to warping, something that is not currently available in any of the existing comprehensive rotorcraft analyses.
Keywords Aerodynamic loads
Aeroelasticity
Airfoil profiles
Displacement
Flight control
Harmonic control
Rotary wing aircraft
Rotors
Simulation
Strain distribution
Trailing edge flaps

 
Source Agency National Aeronautics and Space Administration
NTIS Subject Category 51C - Aircraft
51F - Test Facilities & Equipment
Corporate Author National Aeronautics and Space Administration, Moffett Field, CA. Ames Research Center.
Document Type Conference proceedings
Title Note N/A
NTIS Issue Number 1320
Contract Number N/A

Science and Technology Highlights

See a sampling of the latest scientific, technical and engineering information from NTIS in the NTIS Technical Reports Newsletter

Acrobat Reader Mobile    Acrobat Reader